Oil heater



March 6, 1945.v c. s. REED 2,370,996

OIL HEATER Filed April 2, 1945 2 Sheets- -Sheet 1 INVENTOR C l Z SJZeed 7. 6%

GENT

March 6,1945. Q -REED 2,3709% OIL HEATER Filed April 2, 1945 2 Sheets-Sheet 2 ali its' lzed BY/6% Z @E'NT =1 INVENTOR Patented Mar. 6, 1945 cal-1 s. lieed New York,- N. Y, assignor to 'fIhe Lumnius company, New Yemen. 2.. 2. constration or Delaware Application April2, 1943, Serial rid-481.627

3 Claims.

Thisdnvention relates to a furnace construction. and mor'e particularly to an oil heater f-urnace wherein oil is passed through horizontal tubes positioned in the lower part of the-furnace and subjected to heating for the purposes of distillati'o'n, cracking or'the like. i

object of the invention is to construct an o'il'heating tube furnace of non-strategic materials at a minimum of cost and substantiallydevoid of-metal fittings and accessories customarily inconstructing oil heating furnaces. In the present construction, the oil tubes are substantially the 'only metallic parts utilized.

A further object of the invention is to cons struct an oil heater in the form of an inverted caten'ary which will be self-sustaining and wherein the entire furnace construction is under simple compression.

A still further object of the invention is to provide an oil heater furnace wherein the heat sources, or burners, are located in the upper portion of the arch of the inverted catenary whereby an essentially uniform downward radiation of heat from the furnace walls to the horizontal tubes located across the bottom of the furnace is obtained. This improved construction and arrangement of the elements, namely the location of the heat sources or burners for supplying heat initially to the chamber within the region of the crown of the inverted catenary furnace wall, and the horizontally arranged tubes adjacent the widest portion of the catenary wall, provides for distributed downward reflection of heat from said wall to the tubes. In addition to such provision for radiant heating .of the tubes provision is made for supplying heat to the tubes by convection, by passage of the combustion gases over and between the tubes.

In the drawings:

Figure 1 is a vertical cross-section showing the inverted catenary form of the furnace with its rows of staggered oil heating tubes and the bumers positioned in the upper part of the inverted catenary.

Figure 2 is a longitudinal section through the furnace illustrating the position of the rows of oil heating tubes in the lower part of the furnace and the plurality of lateral gas exhaust ducts.

Preferably the furnace consists of a non-metallic inverted catenary structure I composed of suitable refractory blocks or bricks 3 laid up in two layers 1 and 9 and supported alon the londrawings. In the preferred embodiment, me-mner refractory layer 1 of the inverted catenary is slightly separated from the outer layer 9 by an intermediate airspace 13 to takecare ofany differential expansion of the inner and "outer walls of the inverted catenary. The exterior of the furnace may be covered with "a layer of suitable insulating and weatherproofing material. 11 which is loosely bonded to the. outside of the catenary arch. This form of construction is entirely self-supporting and the masonry composing the inverted catenary is primarily in simple compression The ends of the inverted catenary archg-are closed by refractory walls and, as shown in Figure 2, these end walls are independent of the catena'ry and, consequently, do not support any of the weight thereof while the abutting edges of the end walls and inverted catenary are provided with suitable expansion joints I1.

The furnace may be heated through the medium of a number of heat sources such as oil or gas burners I9 positioned through one or both of the end walls adjacent the upper or intrados portion or crown of the inverted catenary. Oil

. heating tubes 2| supported on transverse bridge gitudinal side edges on foundation walls 5, al-

though a single course of masonry may be used instead of the double wall illustrated in the walls 23 are arranged across the floor area near the base of the furnace, although sumciently ele-, vated thereabove to form a longitudinal plenum chamber 25 thereunder throughout the entire length of the furnace between the end walls thereof. As shown, the products of combustion are exhausted from the furnace through a plurality of lateral ducts 21, although it will be understood that the gases may be carried off through a longitudinal passage, or the like, to a suitable stack.

The radiantly heated oil tubes 21 are generally arranged in two spaced horizontal rows and in staggered relation, although, if desired, a bank of convection heated tubes may be positioned below the radiant heated tubes, whereby the hot descending gases flow evenly around the surfaces of the tubes to uniformly heat the same. The position of the upper burners I9 is such that the hot gases generated create a uniform downward radiation of heat from the furnace walls-to the tubes over the whole tube area. After contact ing the tubes, the gases pass into lower plenum chamber 25 and thence from the chamber through discharge ducts 21.

While the oil heating tubes 2| are illustrated as carrying diffusion bafiles, as described and claimed in the copending applications of Otto C.

Schauble, Serial Nos. 445,128 and 475,959, it will,

be understood by those skilled in the art that any suitable form of baffle or diffusion device ma} be used to obtain a distribution of the flow of hot combustion gases for maximum transfer of heat to the tubing.

As before stated, the salient feature of this invention is the construction of an oil heater furnace composed substantially entirely of refractory material in the form of an inverted catenary that is self-supporting and places'the entire'con structio-n in simple compression.

Iclaim:

1. In an oil heater including a furnace chani-j ber, with oil tubing thereinand burner means for supplying heat to the chamber; a continuous wall structure defining the roof and "opposite sides of said chamber and formed of refractory.

' blocks laid up to define an invertedcatenaryvextending substantially tothe bottom of thechamber, foundation means supporting said wall struc ture at the extremities of the catenary, said'burm er means being disposed to supply heat to the chamberinitially within the region of the crown. portion of the catenary for distributed downward reflection of the heat from the crown and sides of the catenary, and means supporting said oil I tubing in ahorizontal bank extending between opposite lower portions of the catenary to receive directly said downwardly reflected heat, said bank being spaced upwardly from the floor of the heater to afford therebeneath. a .plenum space 1 1 within the heatensaid space having an. outlet,

and the bank comprising a series of reaches of the tubing horizontally spaced to provide a series f intertube spaces for fiowof combustion gases downwardly to the plenumspace, whereby the bank willbe heated by both convection and radiation;

' crown portion of the catenary for downward reflection of the heat from the crown and sides of the catenary, and means supporting said oil tubing in a horizontal bank extending between opposite lower portions of the catenary to receive directly'said downwardly reflected heat.

3; In an oil heater including a furnace chamber with oil tubing therein and means for supplying heat to the chamber; 'a continuous wall structure; defining the roof and opposite sides of said chamber and formed of two spaced, pare allel courses of refractory blocks laid up todefine'aninverted catenary extending substantially to the bottom of the chamber,,foundationmeans supporting said wall structure at the, extremi-, ties of the catenary, said heating means being disposed to supply heat to the chamber initially within the region of the crown portion of the catenary for downward reflection of the heat fromsthe vcrown and sides of the catenary, jand means supporting said oil tubing in a horizontal bank extending between opposite lower -.p.ortions of the catenary to receive directly said down- 3 wardly reflected heat. t

Y CARL s. 'REEDQI 

